当前位置: X-MOL 学术Langmuir › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Cyclobutane Scaffold in Bolaamphiphiles: Effect of Diastereoisomerism and Regiochemistry on Their Surface Activity Aggregate Structure
Langmuir ( IF 3.7 ) Pub Date : 2018-09-01 00:00:00 , DOI: 10.1021/acs.langmuir.8b01462
Bernat Pi-Boleda 1 , Alessandro Sorrenti 1 , Marta Sans 1 , Ona Illa 1 , Ramon Pons 2 , Vicenç Branchadell 1 , Rosa M. Ortuño 1
Affiliation  

Cationic bolaamphiphiles have been synthesized starting from meso cis- or chiral trans-1,2-difunctionalized cyclobutane derivatives. They include cis/trans pairs of diastereoisomers, of N- or C-centered bisamides. The goal of this work was to investigate the influence of stereochemistry and regiochemistry on their abilities as surfactants and self-assembly. Very large differences in surface coverage (2-fold), critical micellar concentration (cmc, up to 2 orders of magnitude), and aggregate structure (from lamellae to fibers) for the four molecules are remarkable due to regio- and stereochemistry differences. Computational calculations were carried out to rationalize the experimental findings and a new methodology has been developed to calculate the structure of these bolaamphiphiles at the surface. Although the four surfactants adopt a wicket-like conformation, for N-centered trans, the distance between polar heads is much larger than that for the other three molecules, as suggested by calculations. We have shown that the interplay between the regiochemistry and stereoisomerism, enhanced by rigidity of the cyclobutane ring, affects different physicochemical properties quite differently. That is, the cmc value is mainly governed by stereochemistry, with regiochemistry only modulating this value. On the other hand, regiochemistry definitely governs the morphology of the supramolecular aggregates (i.e., long fibers versus plates or spherical assemblies), with stereochemistry finely modulating their structural parameters. All these results must help in the rational design of new bolaamphiphiles with predictable properties and useful potential applications.

中文翻译:

Bolaamphiphiles中的环丁烷支架:非对映异构和区域化学对其表面活性聚集结构的影响

已从中观顺式或手性反式合成了阳离子双性两亲-1,2-双官能化的环丁烷衍生物。它们包括N-或C-中心的双酰胺的非对映异构体的顺/反对。这项工作的目的是研究立体化学和区域化学对它们作为表面活性剂和自组装能力的影响。由于区域和立体化学上的差异,这四个分子的表面覆盖率(2倍),临界胶束浓度(cmc,最高达2个数量级)和聚集体结构(从薄片到纤维)的差异非常大。进行了计算计算以使实验结果合理化,并且已经开发出一种新的方法来计算这些表面上的两亲两亲物的结构。尽管四种表面活性剂采用了类维克特构象,但对于以N为中心的反式,计算表明,极头之间的距离比其他三个分子大得多。我们已经表明,环丁烷环的刚性增强了区域化学和立体异构之间的相互作用,对不同的物理化学性质的影响也大不相同。也就是说,cmc值主要受立体化学控制,而区域化学仅调节该值。另一方面,区域化学绝对控制着超分子聚集体的形态(即长纤维相对于板或球形组装体),而立体化学可以很好地调节其结构参数。所有这些结果必须有助于合理设计具有可预测特性和有用潜在应用的新双亲两亲物。我们已经表明,环丁烷环的刚性增强了区域化学和立体异构之间的相互作用,对不同的物理化学性质的影响也大不相同。也就是说,cmc值主要受立体化学控制,而区域化学仅调节该值。另一方面,区域化学绝对控制着超分子聚集体的形态(即长纤维相对于板或球形组装体),而立体化学可以很好地调节其结构参数。所有这些结果必须有助于合理设计具有可预测特性和有用潜在应用的新双亲两亲物。我们已经表明,环丁烷环的刚性增强了区域化学和立体异构之间的相互作用,对不同的物理化学性质的影响也大不相同。也就是说,cmc值主要受立体化学控制,而区域化学仅调节该值。另一方面,区域化学绝对控制着超分子聚集体的形态(即长纤维相对于板或球形组装体),而立体化学可以很好地调节其结构参数。所有这些结果必须有助于合理设计具有可预测特性和有用潜在应用的新双亲两亲物。cmc值主要受立体化学控制,而区域化学仅调节该值。另一方面,区域化学绝对控制着超分子聚集体的形态(即长纤维相对于板或球形组装体),而立体化学可以很好地调节其结构参数。所有这些结果必须有助于合理设计具有可预测特性和有用潜在应用的新双亲两亲物。cmc值主要受立体化学控制,而区域化学仅调节该值。另一方面,区域化学绝对控制着超分子聚集体的形态(即长纤维相对于板或球形组装体),而立体化学可以很好地调节其结构参数。所有这些结果必须有助于合理设计具有可预测特性和有用潜在应用的新双亲两亲物。
更新日期:2018-09-01
down
wechat
bug